SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b128718de97a7012ea5f3cf29270dbc8f36a62a360095ce494af122186085aa6' 
  AND token = 'hdcVPaOOl6pi3DPivO9PlEzxAlDAxsnsUan2cq3ZK4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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