SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a501c913ebfbcf1d390b87f91956e8838ee24163044c72ceefc7e4c442d24981' 
  AND token = 'PZvOJgt6sqEVmcOqfoDswUmSH4It3hc++v//u+nHqrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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