SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6df0be5c7e5e1f6b8250a80eb0a595f2634b906bfb303537574ae1ef638d7b28' 
  AND token = 'jznTISEo/sLA4izISsvpuFTAFZ/ZStwYDa1bJ/qBkzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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