SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5103ef4e97455b6a9199baff0d46640656fe90bf321ddc9d0c3d93f9c1c780a1' 
  AND token = 'XLdlOUmfi125Dh0KDmLrsbzvk73yNPAQM1oCeIGvV0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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