SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cef9cf3f7f5b515ae1787d4310287c39279fa020d20fd4c4244f56b4a608b352' 
  AND token = 'h0UrH4ilOY4iEEiGL6yseJJxt+M2pMUV5X2w2kyJ8Ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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