SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8e07c18c0516cc60987aa14ac8f2ceec9eca354404fa46b72a107794159b2c5' 
  AND token = '9i/jzCCxXQOr12IsiD4nMhqXuoNdjg1SSzzSWxLOOi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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