SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '275366aa371f4429a16f804c3422d84ff57fb606e6e0befe33436e83711f4a04' 
  AND token = 'fRdbu34mMeuAuaFbqlVUEXw0n9JBeUbupZVt3RbzLNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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