SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d354ab48e0fd5e81c22ebf7c54687768cda11197bd70e498ffa04c4f56a69b' 
  AND token = 'AQqCFY+nxSs/a3VKSG5Ij1/HTJu9n4y0EQ7tpWbvQwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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