SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85d1ba505d9589e9e128bb74dac9210159b5c988149bfdd329453170ce650f85' 
  AND token = 'E4Jq3yKv0QDMd0f9j+WNeioxaqZ9vGX0TLBiAxqIFLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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