SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0abd0edc20644d05ddc0ef75abeafa88b51bca1a4a4be1b38b162881b706f99' 
  AND token = 'qFXN8tUouwDwB+L9PegmAxLw/dN2MWE8Ry0l+7AIzQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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