SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2d166eeb2d98e7353712e4db90afa1f55df007962b179bf16374ba2858d1cac' 
  AND token = 'CqjLOPmmsSx/77BM7855StPJBrAqP+glOARAhqSowB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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