SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0705714140c6bd1744cd0d5488b9df3a7d8174f0675afff1bb2dd9b064051c5e' 
  AND token = 'msQfL05wj3UjsVS7ngTurGH+SX3kYZ6hPXEsVAguBOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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