SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7d6aeace3352c867183ad4c5530ddec4011ba064f291ae4813fb6eac2776bc6' 
  AND token = 'iLrLnYnKSkyFvVtGpfUl+md7Zl037zKBiYv2FeSqCPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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