SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3a2088ec7b2cff15d0385c32be2b5eea4106d447adcb033970752a87faeb42cd' 
  AND token = 'EQGysQ0QlNXDmVZrjpA8Pbxo+NZbwhivj3zlNPHg+ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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