SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac6350e166932e3acac1bd58ef87996668534dad42f7c64d384f2f17f92c9049' 
  AND token = 'ReWfgqjPpIIFZO1Nhh4OrKTpL07CuY+zw9w4468OhPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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