SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5699f519b3e0d34014e01863ab90377555db585b01d00293cb57ded054513cca' 
  AND token = 'WMxf9enL5nAEmXVaDeAUkqavwlI/0Br8cnj+Wwqg45A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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