SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1aacdee51ea592ee75ee779a91e134bd153c68b450b504ac6fd3c72569a3521' 
  AND token = 'ZKD2uG8bxqlork1iFS1y8md7sUoG6dT7RS3PtEn2YXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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