SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb8582e535af188fb8c9d2cb92608dde434732ba2eb57efd288f38ecc7e8b96d' 
  AND token = 'MJnLOEC0A801W2VHNCcrSRUd+UqdEA/eDoi1ukqh2i0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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