SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a27948f8c6826499f69477206884505975741ca304ac0fcdf33eb237a1d9d3' 
  AND token = 'XOStmiYpgxykyXN999g2B8+JpQIXSfQODdbyA3AMz7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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