SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c502deb84cfb6c83b27aaf0cc044025f36830b3a151687dd790b607f92ec3a5e' 
  AND token = '/MMwM5dPUutEMJS7GIjvFW5Oi5ZArNSujzJF8DFTloQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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