SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27cc62e25dfc63d5e5ccfa9a80701db88f09ecc270fb9eabb91d2b368c149018' 
  AND token = '2/83UbBX2PRdJbRtiUJBicfCAK2PNeGwu6N6FY7uYKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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