SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d0671b414afada02099b0369de23e86ea188fbba258729daf79b33f16487d90' 
  AND token = 'eLIln6FXciJEOBhQWhVzYQoYKg3seVex3D68m4G+mSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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