SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb48878e85418ff4b141eae9078e50d83410f15b780716aeb1e099c42f3f68a' 
  AND token = 'nw2VcQVkqK3pKrVc3joP/VycR5RGDfJwT4YVFEfEXo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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