SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '42e2362fee1a0500ebc4a04723c0efcbdfd6bc57f4c0d49a7fe744058d7924bc' 
  AND token = 'BDHG8k9m3t/IJyhBR2zCz8oMOvKVVMJxX0BA4jJWTjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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