SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c3327c7a37cbb9c66023755218d9c9665905808a96cb32d8051c47b54db6afa' 
  AND token = 'j9g4BB48x+nOGxUI/0bQJLCyxfgmXlLIg2BCMULGiC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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