SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f89bca776dfb831740289ef25ddc241cb16434da34518ba64a415236c6274711' 
  AND token = 'F3i0RZ6i6u4z3qgEfBRVfJ/tDgLiNLUL8uxvXioTf2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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