SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bb7c2a58f6fb985173e9fc4b00ddbfbd6cccccda93cbef2b385c10799b7e2d94' 
  AND token = 'Ra5yuQ/UzWxS1LHZWoRM+aQNdAWoUlNU+4N92UjXalQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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