SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daef3f640e6256b6a4099efe7f20fff1e3d280b1d2c3999f318c47f8389bde6c' 
  AND token = 'OZr9PcJBFZKonCGU/+Ij5owIPfK/gb+OgG513lTY9bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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