SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ebf4a8289e697f680ad656f386753cc6bb687a43b253f97ff834c4877fd5315' 
  AND token = 'wHNTN+DOyQxFKXlYwzAvO+sS7vjzC3/dDkkTZ5D6ydM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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