SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '751d15c05b69a9f9da134978b080ac74545d180b7fa34524481fe6802a5ef5a9' 
  AND token = 'eAkCqkV0SexwTOSF+w4BtAiSxEesyYF3i1vwoyzboV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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