SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df6aeb562d341e07d9a2c1405d31138c314556f29805be4483459a6c904230ce' 
  AND token = 'wJ03EveMhjE6iYSzp+ykk1N3l9UfNkEBwkw2NLE9Lec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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