SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cacd25dc9413e0a8d785d48ff678ec7854d88d3fd21aef5689d170b6be8f795' 
  AND token = 'o9yvWLU5ZMkVSPINoJLKal3DNSUHoMWeIbwZ1g9ku2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}