SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dbc9ef772b3ef17830fefcbf6f451cac9ab799399bc328141c532a1f5fd5f42' 
  AND token = 'NbdHRobgbpNtSi/Sv6OuIVNI+ZTrltSXJ0RvH2GJaB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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