SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9075716ac3099ae3763f71b2e967c32525a929abe0a98a4adcdec59fbd5bcfc' 
  AND token = '7qRXHNF0/6PtPoK3Q/PyFqUBqCpviFmAk6Mt0/S2J4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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