SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '839d69022e98b2046810fde83bcf7d36c7bbb441edd923343f088d34a5d5ef04' 
  AND token = 'mlTboMx6VBEQqVNqRJWh2NTrzl5Ly7dPIZUEvEW+dqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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