SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce1e6c89d34d298df8fd76ae2267c26a79500595304ee84b0c930a977b9a592c' 
  AND token = 'mL8pDKoEiSmriKlWneuUa01WRWrTPNiUFWSqZc0Ql3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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