SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6f545623c20eff3fe8fa9f0efaee8880ed277ca0dc890eb47768b29c7dc41f2' 
  AND token = 'WDKAHcYfIK4gLQ8CJ2veg/tBNefINq2fL/SQEODiVOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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