SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cbbdbf2bc0c26d27cec462bec3a485a710e3e5199fd464707fcfe78d16b45c5' 
  AND token = 'meNWZkxSvVtJkPJnX6R/wQ0wCpsxNW+5q5TMsxHEksM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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