SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1b605336a2fef7bcdabb0fd97bc23fdc7063fb9e4ce18500a63053da3126142' 
  AND token = 'bYOS1gclUSnH2jgV1aeW54tyNRRipa90F3x9zUYnTvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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