SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb951a2874bf3b9ca03e15e0e1981844c886d0fce6078ce934dfb03adc32bac5' 
  AND token = '9aGS05KaLYNrhtZDQ0uR7enBUUalTQTlVUnKuhLmiNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}