SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '916f7bf624f6b2321981933777d456ed2cf7c7c191b97ebd3378bb2f9bbee948' 
  AND token = 'YaeLnGAOOUOJ3wSp/bqKTLBPOhwz3blE3phwO1NP170=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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