SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7474b1ee31c47d0a5ea214696dff8c35937fcff7b433f1b807e35a6bb590c59f' 
  AND token = 'BC/FO5IwTEIdDX0grsVoRKL4VdV8s3DZ+gEosrXujvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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