SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cf805898b3980aa46375daed183a29776cbb9e3e714ae64869c2603cb3240f0' 
  AND token = 'ozV77mA4lIpLScF4qSx5MJvtXu9xZ3YzSJfFX6GTRS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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