SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba87fccb65315169112eb1c204083d75a47903f2d38655567c05219bd385b560' 
  AND token = 'rr4Pb6llOVqCNReqOOx1DYRb+Rq68avMfORjaNRkYcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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