SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9a2d9b82101302ccfec60707d7abfe213e69c9fcd2ef229b11ffd729370aea7' 
  AND token = 'ZRujEIMTgh420O7Ynkx9YF/LXUhtPmtRQfJDnrTPna4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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