SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8783e37cfafe91741b5a7156652945e0fea7d473eebaa40c5e710dcc70b92d66' 
  AND token = 'o+3nmD/DN0L2GbkRvmAZfG0JkFk/RNvGNINkfrDirDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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