SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb0fd255b329ba93630253f7444101b8a4039eb5834bf81e0ac12bd38d8fd86a' 
  AND token = 'o+Nw0rBqgujiFZr8nkowwSF2C97YTzGzWPDzJ51S+5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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