SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3262d0513e479abaa7556d1a0daa84582788549d8dc9b2ea857d4d3401dd06c9' 
  AND token = '3T8adrdVHuPmiqW9yygQRywJqrG41TaFssvuI7ABX0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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