SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e8c87615bbcb3a812fc0145d504f2759e699fa15a7371faa28370681b94e989' 
  AND token = '1+vsOfriLCZ5RiDGF3x1lSYMoUHPz4BG/QP2BOX4vIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}