SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '10b0e87572e4e0b05bd8a40fab4424cdef8b30e5859fb3a323093a41cae9d8e3' 
  AND token = 'ZqwvcjMGDYSspu7Hg0AKNELTlx1HVEobMO+jDtnO/2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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