SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a2ac07b0186cf4f40617b55ccdff79844547218739267d242cf39bf76a61b54' 
  AND token = 'F0UgBGMbV5vlp3hLV59k4GP3/JRXD12p6RynlAjCeio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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