SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5037a760b24d8ee7632185868ad172054c1f1230e5848cbc613897431b759b52' 
  AND token = 'lObgr0VGp8KTLMio+hyNNpZWQj0owe7PZGNR/l+Wf0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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