SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '820127a5c5561db6775003a1c88db48f0a13512df8c805805dc013b50b5412d6' 
  AND token = 'eXw5BIfDs7zRuNOoUaC5y+b/JZ6z0JZcUnJJuD5PjzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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