SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0791efd51504d811c3c769ed361138522bf562e09418f86d4208017a3d5de9c' 
  AND token = 'Zr2T7k8xeMqBFrbJ3IH0sS0NPB4JQ6bsaHjBNht687A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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