SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9dc61480a0f41592ad2d7354bded329fa4faf4f7b4fdc9124c4fd7473d79ebc' 
  AND token = '332qavJeyRLKZr5x9QfQxkLFRSM5UD945SFH2uGTpn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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