SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45618f9f96ac0dead1f828113cde0ccbbba8f3747393ec396d4a25b98af15bfd' 
  AND token = 'ufGnpC2jLoJZ04Fhp//0YIHlnJATAi9gwq+JveikPwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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