SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e749f3950d72f522f7c7dee60c46cca8a221ab31bc9ce39d2d5e8467c116a2a2' 
  AND token = 'FFF4iFyLUUdsk/nxdWrDNdtiMObEBFtoLLiguiQlW4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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