SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e68429bb18a07ebb6873ce64b5b10719d36371e58c40c748fb14a45a0f3e9011' 
  AND token = '7xtbdFilDSH6PS8TmnLKzN230sHB8ic0ZxsPFEK1uPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}